Structures and physicochemical properties of acylation chitosan

In this study we aim to develop a new utilization of the chitosan. The chit osan was acylated by glutaric anhydride. The acylation at the amino groups, of the chitosan was saturated with comparatively little dosage of glutaric anhydride. The reaction at the hydroxyl groups increased with increasing t he dosage of glutaric anhydride. The elastic modulus of hydrogel film depen ded on the change of water content which accompanied the acylation, i.e. th e elastic modulus decreased with increasing water content. The swelling ext ension of a film was measured in aqueous solutions of various pH. The exten sion decreases with increasing acylation in low pH, while it increases in h igh pH. This is because the number of carboxyl groups increases with increa sing acylation degree. The contact angle of the hydrogel film showed a maxi mum with the increase of acylation.